Semantic Ambiguity

• Sentinel values:

  • Using null to mean "it's not there", or "it's there, but it's empty."
  • Using -1 to indicate something went wrong.
  • Using -1 to indicate a variable has not been given a proper value.

• Data type represents different concepts.

  • If you want X, define fields A, B, and C.
  • If you want Y, define fields A, B, D, and E.